Portico 5024 By: Quad Microphone Amplifier Serial #: Operations Manual 1
Portico 5024: Quad Microphone Amplifier Thank you for your purchase of the 5024 Quad Mic Amp. Everyone at Rupert Neve Designs hope you enjoy using this tool as much as we have enjoyed designing and building it. Please take note of the following list of safety concerns and power requirements before the use of this or any Portico Series product. Safety It’s usual to provide a list of “do’s and don’ts” under this heading but mostly these amount to common sense issues.
Portico 5024: Block Diagram 3
MICROPHONE PREAMPLIFIER DESIGN NOTES In former years, before the introduction of solid state amplifiers, transformers were necessary to step up to the very high input impedance of tubes, and to provide a balanced input for the microphone line.
In the early 1960’s when the “Pop” music scene was exploding and sound levels in the Studio became very high, there was concern that the head amplifiers in Condenser microphones would overload if the Console input impedance was too low. In the early days of Consoles I was asked to provide higher input impedance than the normal 1,000 ohms. This of course, resulted in less “step-up” in the Console input transformer and there were then fears that we would lose out at the other end of the scale; Noise.
Portico 5024: Front Panel Gain +66dB in 6dB increments with +/- 6dB Trim 30 Silk Adds nostalgic warmth and presence to signals when engaged Trim +/- 6dB level control 36 18 0dB 60 6 Thru Parallel Thru output for use with an external amplifier Portico 5024: Back Panel 54 12 66 DI Transformer Isolated Hi-Z, DI Input 48 18 54 60 6 0dB AC IN 100-240VAC input 50/60Hz .
C IN LED Meters 8 Point LED Peak Meters 30 36 HPF Engages the HPF circuitry 42 24 30 48 18 42 48 18 60 0dB 36 24 54 12 6 HPS Frequency Selects between 30Hz and 90Hz for the HPF 54 12 66 Rupert Neve Designs 60 6 0dB 66 Mute M/S Changes CH 3 & 4 from independent to Mid (CH 3) and Side (CH 4) Polarity Reverses the polarity of the source material Mutes the output signal Mic Input TLA & Transformer Balanced, 10K Ohm 1=GND 2=Hot 3=Cold 4 LINE OUT MIC IN 3 LINE OUT MIC IN 2 LINE
sound may well have a flawed data bank! Quality recording equipment should be capable of retaining “natural” sound and this is indeed the traditional measuring stick. And “creative” musical equipment should provide the tools to manipulate the sound to enhance the emotional appeal of the music without destroying it. Memory and knowledge of real acoustic and musical events may be the biggest tool and advantage any recording engineer may possess.
5024 is connected. MIC GAIN A 12-way precision rotary switch covering from Line (0) and Mic from 0 to 66 dB in 6 dB steps. TRIM A continuously variable pot provides +/- 6dB level adjustment on each channel IN and THRU 1/4” JACKS These 2 jacks on both CH1 & CH2 are used for DIRECT INJECTION (DI) or INSTRUMENT inputs, and are simply paralleled and wired together. Inserting a plug into either jack breaks the normal MIC input and the user has the full range of MIC GAIN and TRIM.
SPECIFICATIONS Frequency Response: Main Output, no load, –0.2 dB @ 10 Hz –3 dB @ 160 kHz Noise: Measured at Main Output, unweighted, 22Hz-22kHz, Terminated 150 Ohms. With gain at unity better than –100 dBu With gain at 66 dB better than –62 dBu Equivalent Input Noise better than –128 dBu Noise Factor 1.5dB High Pass Filter: Frequency: Slope: 30Hz or 90Hz 12 dB/Octave Bessel Maximum Output Level: Maximum output from 20 Hz to 40 kHz is +26 dBu.
PRODUCT WARRANTY Rupert Neve Designs warrants this product to be free from defects in materials and workmanship for a period of one (1) year from date of purchase, and agrees to remedy any defect identified within such one year period by, at our option, repairing or replacing the product.
